1. Field of the Invention
The present invention relates to a crankshaft having eccentric sections at both ends.
This application is based on Japanese Patent Application No. 2007-011203, the content of which is incorporated herein by reference.
2. Description of Related Art
As a crankshaft having eccentric sections respectively at both ends, there has been known one disclosed in Japanese Patent Application Laid-Open No. 2006-132332 for example.
However, the crankshaft disclosed in Japanese Patent Application Laid-Open No. 2006-132332 has required processes of preparing the crankshaft divided in the middle of the shaft in advance and of assembling the crankshaft again after inserting a motor rotor. Therefore, it has had problems that its assembly process is complicated, prolonging work hours required for the assembly process and increasing a manufacturing cost.
It also had a problem that strength of the crankshaft drops because it has the structure in which it is divided in the middle of the shaft.
Furthermore, it had such problems that it may cause decentering in the crankshaft and the performance of the crankshaft drops because it had the structure in which it is divided in the middle of the shaft.